Pentecost grew from a festival marking the Middle Eastern year’s first grain harvest and a sacrifice to the gods.

In ancient Palestine, once called Canaan, this first-fruit sacrifice linked to religions of the gods of power in farming and fertility. As Jews decided to follow the one true God, they were instructed to bring the wheat harvest’s “first fruits” in thanksgiving to God.

As Jewish kings started the centuries-long process of centralizing religious activity in Jerusalem, they brought this pilgrimage and sacrifice there. To them, the 50-day period was the week's worth of weeks after Passover.

Passover, using unleavened bread, recalled God’s rescue from hard times. Pentecost, which celebrated a blessing of harvest, was symbolized by leavening the bread.

The festival began to take on another religious role around the time of the exile. Because Exodus 19:1 describes the Jewish people’s arrival at Sinai as being about that time of year, Pentecost marked the giving of the Torah at Sinai. Over time, the Torah became more prominent in Feast of Weeks celebrations.

Fast-forward to Jesus' time.

As Luke states in Acts 1 and 2, more than 100 believers gathered after Jesus returned to the Father.

They talked, remembered, prayed and wondered what was next. On the morning of Pentecost, they told the people they met about Jesus.

Each person heard the witnesses speak in their own language — if they carefully listened; otherwise, they heard babbling. They spread, for the first time in full form, the good news of Jesus.

However, it was more than words. The Holy Spirit, in the ears and the hearts of those who listened, carried the words with power and authority. About 3,000 new people joined believers' ranks.

Pentecost wasn’t the first time the Spirit was active. The Spirit had been working all along in humans who listened.

However, Pentecost was the first day that the Spirit took hold of Christ’s followers as a group or "body," and came to stay.

For the first time, the Spirit's raw power was there in anyone who followed Christ.